Governing mechanism.



R. B. OWENS.

GOVERNING MECHANISM.

APPLICATION FILED MAY7, 1907.

Patented Mar. 29, 1910.

2 SHEETS-SHEET 1.

/7? van t or: Robert A?' Owens,

M'Lnesses:

M w.. PNOTO-LITWORAPHER:, WASH UNITED STATES PATENT oEEIoE.

ROBERT B. OWENS, OF MONTREAL, QUEBEC, CANADA, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

GOVERNING MECHANISM.

Specification of Letters Patent.

Application filed May 7, 107.

Patented Mar. 29, 1910.

Serial No. 372,324.

To all whom it may concern:

Be it known that I, ROBERT B. QWENS, a citizen of the United States,residing at Montreal, Province of Quebec, Canada, have invented certainnew and useful Improvements in Governing Mechanisms, of which thefollowing is a specification.

The present invention relates to governing mechanisms and moreespecially to those intended for controlling the admission of motivefluid to elastic fluid turbines, although it is not limited thereto.

The object of the invention is to provide a governing mechanism ofimproved con struction.

In carrying out my invention as applied, for example, to elastic fluidturbines, I mount on the turbine shaft or on a shaft driven thereby, therotating member of a small electric generator, the stationary memherbeing in cooperative relation with respect thereto, as for example,surrounding the same. Bypreference, the rotating member is composed of amass of iron having suitable polar projections, and is unwound so as toavoid the necessity of sliprings bet-ween it and an external circuitwhich always require more or less attention on the part of the stationattendant. By avoiding the use of any winding on the rotating member,the latter can be of very simple construction, and may be made ruggedenough to withstand centrifugal strains.

The stationary member is provided with a suitable field winding excitedfrom a source, such, for example, as a storage battery, and also anarmature winding. By preference the field magnet works onthe lowerportion of the saturation curve so that the generator will be moresensitive in its operation than, would be the case if it worked on theupper portion of said curve. Such a construction also results in a lowfirst cost and requires little or no attention from the stationattendant. It avoids the complications of a speed-governor havingcentrifugal weights, springs, etc., and also the lag commonly found insuch a device owing to the friction of the parts moving with respect toone another.

As the speed of the turbine changes with changes in load, the potentialand the amount of current induced in the armature winding of thestationary member will correspondingly change. I utilize the change incurrentflow to actuate a device which, in turn, controls the action of aregulator which may be the valve or valves employed to regulate theadmission of motive fluid to a turbine, or the flow of the fluid throughits stages or both.

The device acted upon by the current instead of being located on themachine itself is preferably situated at a point remote therefrom whereit is out of the influence of the machine being governed, and is readilyaccessible. For example, it may be mounted on the switch board where itwill be under the observation of the switch-board attendant and where itcan be adjusted by simple means and without interfering with theoperation of the turbine or other ma chine being governed.

In the preferred form of the device, two hot-wire units are provided. Inthe simplest form of the invention each of these units comprises asingle wire, but where greater power or sensitiveness is required, eachmay be made of a plurality of wires and arranged to work directly orthrough levers or other transmitting devices. One of these units isconnected to the armature winding of the generator referred to and maybe termed the active unit; the other is con nected to the same batteryor other source of supply which excites the field magnet of saidgenerator, and may be termed the compensating unit. By reason of thisconstruction any change in potential of the battery or other sourcefurnishing the exciting current will have thesame effect on both units,and so also will any change in the room temperature.

In using the term hot-wire units, it is not to be understood that theyever get very hot, for such is not the case. They are of such character,however, that they will expand and contract a moderate amount withcomparatively small changes in current strength. Various kinds of wirecan be used in their manufacture, the cross-section, length andresistance being governed by the amount of current normally flowingthrough them.

It is desirable to keep the temperature of the units as low as possibleat all times consistent with satisfactory operation so that thealternate heating and cooling will not injure them.

Mounted on or actuated by the said hotwire units is a contact devicearranged to make or break the circuit of an electric motor, the latterbeing connected directly or through suitable gearing with a shaft thatactuates the valve or valves of the turbine, or the governing mechanismof any other machine being governed. Stationary contacts are providedwhich are connected to the windings of the motor, and are so arrangedwith respect to the hot-wire actuated device that the motor will becaused torevolve in the proper direction to accomplish the desiredregulation. The said device and contacts form a relay, and the currentfor actuating the motor does not therefore have to flow through thehot-wire units or the device carried thereby.

The hotwire units and the contact device actuated thereby are inclosedin a small casing mounted on the switch-board, and connected byconductors with the generator located on the turbine and also with theswitches controlling the motor and the emergency valve mechanism, thelatter acting when, for any reason, the speed of the turbine exceeds apredetermined amount. The circuit wires may be inclosed in metal tubesto protect them against injury. This arrangement does away with themechanical complications of existing structures, and keeps the thermalelement of the system away from the heat radiating from the turbine.

The wire or wires forming the hot-Wire units are kept taut by suitablesprings or equivalent devices, and since the position of the units maychange bodily by a small amount with changes in current strength of thebattery or other exciting source, and also with changes in roomtemperature, I mount the stationary contacts on a support or supports insuch manner that their positions are changed with changes in position ofthe contact device.

In the accompanying drawings, which illustrate one of the embodiments ofthe invention, Figure 1 is a view showing a turbine fitted with myimproved governing mechanism; Fig. 2 is a perspective view, made in amore or less diagrammaticmanner, of the hot-wire units and contactdevice; and Fig. 8 is a diagram of the circuits, also showing the valvemechanism.

1 represents a turbine of any suitable construction or type, the oneillustrated being a Curtis turbine. Mounted in the dome 2 thereof is asmall electric generator 3 which is driven by the turbine shaft 4.Mounted 011 the switch-board or other suitable sup- K port distant. fromthe turbine are the hotwire units.

Referring to Fig. 2, 5 represents a base upon which are mounted twoupright standards 6 and 7, each having a disk of insulation 8 and twoflat springs 9 and 10 connected to the hot-wire units 11 and 12. Thetension of each spring can be adjusted by a screw 13. The disks andstandards are bored to permit the hot-wire units to pass through themwithout contact, thereby leaving them free to expand and contract.Preferably, but not necessarily, the units 11 and 12 occupy horizontalpositions so that all parts of the units are subjected to the sametemperature conditions. The units are kept taut by flat springs 14connected thereto by straps 14k and adjustably mounted in supports 15.Each spring engages a head 16 mounted to move vertically in a guide 17.To the left hand head is secured a frame 18 that supports threeinsulated sets of contacts 19, 20; 21, 22; and 23, 24. The first pair ofcontacts is connected in circuit in such manner that when closed, thevalve mechanism will increase the supply of steam or other motive fluidto the turbine, or energy of any sort to the controlled device in eventof its being used in other connections. The second pair of connectionsis arranged when closed to give the opposite effect, and the third pairis arranged to close the circuit of a magnet that releases the emergencyvalve, and permits it to close by gravity, a spring or fluid pressure,as desired. Mounted on the said units in a manner to be moved thereby isa contact device or arm 25. hen in the upper position it closes theupper pair of contacts, when in the lower normal position, the lowerpair of contacts, when in an abnormally low position the emergencycontacts, and when midway the circuits are open and the valve mechanismis at rest. This contact device is divided into two parts electricallyby the body of insulation 26. There is a certain amount of flexibilityin the contact device so that upon failure of the valve mechanism to actquickly enough, the emergency contacts 23 and 24: will be closed.

It is apparent that for a very small change in length of the activeunit. 11 there will be a considerable movement of the free end of thecontact device, the compensating unit 12 acting as a fulcrum. Thechanges in length of the units due to changes in strength of theexciting battery are small and take place gradually over a considerableperiod of time, while a change due to a change in speed of the turbineis a relatively sudden one. It is evident that instead of using aspring, a weight or equivalent means may be employed for keeping theunits taut under changes in current strength.

Referring to Fig. 3. 27 represents the stationary member of thegenerator 3 and 28 the rotor, mounted on the turbine shaft 4. Thestationary member is provided with a field winding excited by thebattery 29 which includes an adjustable resistance 30 for varying theexcitation. It is also provided with an armature Winding connected bythe wires 31 and 32 with the active hotwire unit 11. In the circuit isincluded an adjustable resistance 33. The battery is also connected bythe conductors 34 and 35 with the compensating unit 12 so that changesin its strength act on both the generator and the compensating unit. Thecircuit also contains an adjustable resistance 36 whereby the eflect ofthe battery on the compensating unit can be changed.

37 and 38 represent the mains of any suitable source of supply of amoderate voltage for furnishing the necessary power to operate the motor39, the latter being mechanically connected directly or indirectly tothe cam shaft 10 which actuates the valves 41 one after the other. Thesevalves are attached to levers 42 and are raised by the cams and closedby the outside springs 43. The field winding 4.4 of the motor isconnected to the circuit of the supply mains and includes an adjustableresistance 45. The armature circuit is normally open and is controlledby magnetically actuated switches 46 and 47, and the circuit of thesemagnets is under the control of the active hot-wire unit through thecontact device 25. When the device is in the position shown the armaturecircuit is open. Assuming that" the speed of the turbine increases therewill be an increase of current in the armature circuit of the generator3 which will increase the temperature and length of the hot-wire unit 11by a certain amount, and since the compensating unit 12 remains fixed inlength under such a condition it acts as a fulcrum, and the spring 14will pull the unit 11 down, and at the same time, move the contactdevice 25, and close the circuit of the relay magnet 47. hen thusenergized, its core is raised, and the contacts controlled thereby areclosed and the circuit will be from the wire 37 to wire 48, thence towire 19 and the armature of the motor, returning by the wires 50 and 51to the main 38. This will cause the motor to rotate toward the observerand permit one valve after the other to close until the proper amount ofmotive fluid is being supplied to the turbine. \Vhen the speed of theturbine returns to normal the flow of current through the active unitwill become normal and the motor circuit will be broken. Assuming that,for any reason, the motor fails to operate or does not respond quicklyenough to specified conditions, the contact device 25 will close thecircuit of the contacts 23, 24 and energize the magnet This closes thecircuit of the magnet 53 and the latter attracts its armature and raisesthe latch 54 and permits the weight 55 to fall and close the emergencyvalve 56, and thus cut off further supply of fluid to the turbine.

Assuming that the speed of the turbine falls, the amount of currentflowing through the hot-wire of the unit 11 is decreased which causesthe same to shorten, and in so doing raise the outer end of the contactdevice and close the circuit of the contacts 19 and 20, thus energizingthe coil of-the switch 46. WVhen this switch is closed, .current flowsfrom the main 37 and wire 57 to the wire 50 and the armature of themotor, returning by the wires 19 and 58 to the main 38. It will beobserved that under this condition the direction of rotation of themotor is opposite that previously described, and one or more of thevalves will be opened to admit more fluid to the turbine until the speedagain becomes normal and the flow through the active unit becomesnormal.

In the construction shown, each of the valves 41 controls the passage offluid to an expanding nozzle 59 which, in turn, dis charges fluidagainst the wheel buckets 60. If desired, the valve may control morethan a single nozzle or nozzle section.

I have shown the regulating mechanism of the turbine as being actuatedby an electric motor, since this is a wry simple and effectivearrangement, but it is evident that other means may be employed for thispurpose. The construction described requires electric switches forcontrolling the motor circuits, and so they have been illustrated, butin event of a ditterent form of motor being employed, or a differentform of regulating mechanism, either for a turbine or other apparatus,it is within the scope of my invention to make the necessary changes ormodifications in the controlling member actuated by the hot-wire units.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof;but I desire to have it understood that the apparatus shown is onlyillustrative, and that the invention can be carried out by other means.

hat I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator moving with said apparatus, asource of current for exclting the generator, a means sensitive to thecurrent produced by the generator, a regulator for the apparatusresponsive to said means, and a second means sensitive to cur rentflowing through said source which as the excitation varies modifies theaction of the first means on the regulator.

2. In a governing mechanism, the combination of a prime mover, anelectric generator driven thereby whose field-magnet of current works onthe lower end of the saturation curve, a source of excitingcurrent forthe l generator, a regulator for the prime mover Cir which is primarilyresponsive to current from the generator and secondarily to varia tionsin current strength of the exciting source.

In a governing mechanism, the combination of a prime mover, an electricgenerator driven thereby whose field-magnet works on the lower end ofthe saturation curve, a source of exciting current for the generator, ameans responsive to temperature changes caused by variations in thecurrent produced by the generator, a means responsive to temperaturechanges due to the current from the exciting source, and a regulatorwhose position is determined primarily by the generator current andsecondarily by the exciting current.

4-. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator driven by said apparatus, asource of excitation for the generator, a means responsive totemperature changes for regulating the apparatus, and a compensatingdevice cooperating with said means whose effective action varies withvariations in the source of excitation.

5. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator moving with said apparatus, asource of supply for exciting said generator, a means responsive tochanges in strength of the current from the generator for regulating thesupply of energy to said apparatus, and a means for compensating forchanges in output of the exciting source.

(3. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator driven by said apparatus, asource of supply for excit iug said generator, a hot-wire unitresponding to changes in output of the generator, a second hotwire unitwhich changes in length with changes in excitation of the generator, anda regulator for said apparatus which is controlled by said units.

7. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator driven by said apparatus, ahot-wire unit receiving current from the generator and expanding andcontracting with changes in current delivered thereby, a contact devicemoved by said unit. contacts adapted to be engaged by said device, asupport for the contacts, a means for moving the support to compensatefor a change in the normal length of the unit, and a regulator for saidapparatus that is under the control of said contact device.

8. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator moving with said apparatus, ahot-wire unit included in the generator circuit, a compensating unit, a

source of current supply which is common to the field of the generatorand the compensating unit, a regulator for said apparatus, and ameansactuated by said units for controlling the action of said regulator.

9. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator moving with said apparatus,the field of which has a low field excitation, a hot-wire unit receivingcurrent from the generator and changing in length with changes incurrent flow, a compensating unit, a source of current supply common tothe field of the generator and the compensating unit, a member carriedby both units, and a regulator for the said apparatus that is under thecontrol of said unit.

10. In a governing mechanism, the combi-. nation of an elastic fluidturbine, a gene 'ator driven thereby, a valve mechanism for the turbine.a hot-wire unit connected to the generator which changes in length withchanges in current flow, a compensating unit also responsive to changesin current How, and a member acted upon by both units for controllingthe valve mechanism.

11. In a governing mechanism, the combination of an apparatus to whichenergy is supplied, an electric generator moving with the apparatus, ahot-wire unit acted upon by current from the generator, a second hotwireunit through which the field currcnt of the generator passes, a membersupported on and moved by the units, means for keeping the units taut, aregulator for the said apparatus, and a motor for actuating theregulator which moves in response to changes in position of the saidmember.

12. In combination, a prime mover, a plurality of successively actingvalves for regulating the passage of motive fluid therethrough, anelectric generator driven by the prime mover, a unit which expands andcontracts with changes in current induced in the generator, acompensating unit responsive to changes in current flow in the excitingcir' cuit of the generator, and an actuator for moving the valvessuccessively that is under the control of said units.

13. In a governing mechanism, the combination of a prime mover, anelectric generator driven thereby, a source of current for exciting thegenerator, a means responsive to variations in current delivered by thegenerator and due to speed changes, a second means responsive to changesin strength of the exciting current, a regulator for the prime mover,and an actuator for the regulator that is primarily controlled by thefirst-mentioned means and secondarily by the last-mentioned means.

14. In a governing mechanism, the combination of av prime mover, anelectric generator driven thereby whose sole purpose is to serve as aspeed-responsive device for the rent from the generator and the excitingprime mover, the field of said generator source. Working on the lowerend of the saturation In Witness whereof, I have hereunto set curve, asource of current for exclting the my hand this third day of May, 1907.

field of the generator, a regulator for the ROBERT B. OWENS. primemover, a motor for actuating the reg \Vitnesses: ulator, and a devicegoverning the motor C. V. HARRINGTON,

Which is differentially acted upon by cur- JOHN BLIZARD.

